General description
Betaine also called trimethylglycine or N,N,N triethylammonium acetate, is an analog of glycine with three methyl groups. It is highly compatible with polymerase chain reaction (PCR) buffer mixture. Betaine is a PCR enhancing reagent that is widely used for improving the yield and specificity of PCR products, especially during the PCR amplification of targets rich in GC content or those that form secondary structures resulting in poor yield. Betaine facilitates DNA strand separation and manages the DNA melting temperature (Tm) difference between the GC and AT pairs in DNA. It stabilizes the dsDNA by equalizing the contribution of GC- and AT-base pairs. Betaine has been broadly used to optimize multiplex and ‘long and accurate’ polymerase chain reaction (LA-PCR). The addition of 1-2 M aqueous betaine to a PCR mixture has been reported to reduce the base pair composition dependence on DNA strand melting.
Application
Betaine solution has been used as a component of loop-mediated isothermal amplification (LAMP) reactions polymerase chain reaction for genomic DNA amplification quantitative polymerase chain reaction (qPCR) for telomere length analysis in the PCR amplification of CGG repeats in the genomic DNA.
-
Final Reaction Concentration: Most protocols use 1.0 M to 1.5 M as a starting point, which can be optimized up to 2.0 M for particularly difficult, GC-rich targets or templates that form tight secondary structures.
-
Volume Calculation (using a 5M stock solution): If you are setting up a standard 20ul or 50ul PCR reaction, you will add enough of your 5M betaine solution to hit that final 1 M–2 M concentration. For example:
- To get 1.0 M final concentration in a 20ul reaction, you need to add 4ul of a 5M betaine stock.
-
To get 1.5 M final concentration in a 20ul reaction, you need to add 6ul of a 5M betaine stock.
Storage:
-
Short-Term Storage: Store at 4oC (refrigerated) for daily or weekly use.
-
Long-Term Storage: Aliquot the solution into smaller volumes and store at -20oC to prevent contamination and repeated freeze-thaw cycles.
Shipping: 5M betaine is a stable aqueous solution and does not require cold-chain (ice or dry ice) shipping. It can be shipped at ambient room temperature.
